The invention relates to a catheter for injecting a fluid or medicine into hollow organs and body cavities, particularly into coronary vessels and arteries, comprising: a catheter tip adapted to be inserted into arteries; a catheter stem; a plurality of injection needles arranged in the catheter tip so as to permit relative movement therebetween, said injection needles having their needle points disposed inside the catheter tip in a retracted position and having them protruding from the catheter tip in an exposed position for applying said fluid or medicine; an operating device mounted on the extracorporal end of the catheter for effecting said relative movement; and openings formed in the catheter tip allowing the injection needles to protrude laterally as well as forwardly; said catheter stem being affixed to one pan of the operating device and the injection needles being affixed to the other part thereof such that relative movement of the two parts toward one another will cause the catheter tip and the injection needles to be displaced one relative to the other so as to move the injection needles from said retracted position to said exposed position.
U.S. Pat. No. 3,598,119 discloses a medical instrument for administering an anaesthetic, wherein an injection needle is guided in an inner coaxial lumen for insertion of the needle under the skin, and a bladder at the distal region can be inflated through an outer coaxial lumen for holding the needle point fixed in position beneath the skin.
The German utility model No. G 89 13 761 discloses an endoscopic injection device for a fibrin agglutinant (FIBRINKLEBER) utilizing three coaxial tubes, the outer one of which serves as a guide for the two inner tubes employed to introduce a two-component fibrin agglutinant which, after commingling at the distal region of the tubes, is applied through an injection needle attached to one of the coaxial tubes.
WO 92 10 142 discloses a catheter including a multi-lumen catheter stem in which needles are longitudinally movable to extend them through openings in the catheter tip and thereby insert them into surrounding tissue for the purpose of introducing therein, through the needles, fiber-optical elements or thermic measuring elements, as the case may be. The hollow needles are suitable for use in inserting flushing and suction appliances.
U.S. Pat. No. 4,578,061 discloses a catheter for injecting a liquid into a vein or artery through an extendible injection needle which is longitudinally movable in the front end of the catheter and communicates with the axial lumen of the catheter so as, when extended, to receive therefrom medication supplied thereto. A two-chamber system provided within the catheter tip and including two coaxial plungers which are telescopically movable one within the other allows one of the plungers to be employed to extend the injection needle, and allows the other plunger to be utilized for applying a predetermined dose of medication through the injection needle.
PCT/EP93/02,829 discloses a catheter of the kind mentioned herein initially. This catheter utilizes a plurality of injection needles which are longitudinally movable in a multi-lumen stem connected to the catheter tip through a sleeve mounted and cemented thereon.
Since a catheter to be used in treating coronary vessels and arteries must be relatively long and, generally, may be about 1.2 m to 1.6 m in length, there will be a considerable amount of friction generated if a plurality of injection needles within the individual lumens of the multi-lumen stem must be moved over the full length of the catheter. If a multi-lumen tube made of a plastics material is being used, such relatively high friction generated over such great length can also create a problem insofar as it may result in undesirable longitudinal elongation or compression making it difficult for the injection needles to be precisely positioned within tissue.
It is the principal object of the invention to obviate these drawbacks.